Stanford, Space Gravity Research Group

Transcription

1 Stanford, Space Gravity Research Group John W. Conklin, Sasha Buchman, and Robert Byer Gravitational science Earth observation: Geodesy, aeronomy Gravity-waves 1

2 Space Gravity Technology Development Drag-free technologies Drag-free flight heritage Gravitational reference sensors Precision metrology Charge control technology Novel materials Precision optics Optical cavities Atomic clocks Grating optical sensors STAR Triad I 1 st drag-free GP-B gyroscope UV LED Sat charge control Iodine stabilized laser fundamental physics 2

3 Science & Technology Implementation on Small Satellites Education Grad, Undergrad 3-5 year projects Student led tasks Science & Technology on Small Satellites Education driven International collaborations Technology Gravitational Reference Sensors Ultra-stable optics Precision Navigation formation flying Science Special/General Relativity Gravitational waves Earth Geodesy/Aeronomy 3

4 Small Sats Tech Demo Program Shadow Sat (partial-funded) UV LED Sat (funded) Optical cavity 2016 (planned) Gravity-waves STAR Drag-free CubeSat (planned) GRACE follow-on LISA LAGRANGE fundamental physics Geodesy, Aeronomy 4

5 TRL 4 TRL 5 Collaboration: Stanford ARC KACST Non Conventional Collaboration Stanford University Basic research supports Basic research at KACST Flight program at ARC Ames Research Center Flight hardware, management TAA with KACST I&T, operations Flight data Flight payload KACST S/C, Launch, basic res. TAA with ARC I&T, operations Basic research with SU 5

6 Technology Objectives Raise TRL levels (4/5 8/9) for Deep UV LEDs ac charge control Beneficiaries: LISA GRACE follow-on Drag-free CubeSat Payload Isolated test mass 16 UV LEDs & photodiodes Charge amp Voltage bias plates ac charge control electronics UV LED Small Satellite mm 6.5 kg Mission Design Spacecraft: Saudi Sat Russian launch in month mission Fully funded ($1.5M) Management NASA ARC: Flight payload, PM, SE, SMA 55 kg 50 W Saudi Sat 3 Demonstrates unconventional international collaboration Stanford: Payload design, SOC KACST: Spacecraft, Launch, MOC 6

7 UV LED Small Sat Payload complete: April 2012 CDR: June 2012 Payload Integration: Oct 2012 Russian launch: ~ May

8 Differential Optical Shadow Sensor (DOSS) Technology Objectives Raise TRL level for miniature highsensitivity displacement sensor nm/hz 1/2 sensitivity No forcing Non-contact Mission Design 2U CubeSat Any orbit Launch ~ month ops Payload funded 2 kg 4 W 2U Cube Light source: Payload SLED, 1545 nm InGaAs quad-photodiode Ultra-low current Difet amp Management Stanford & KACST: Payload, CubeSat structure I&T & Launch: pending 8

9 Science Earth Aeronomy, space weather The Drag-free CubeSat 3U CubeSat Mission Design 4 kg 6 W 3U Cube Demo < m/sec 2 for future Geodesy Earth observation Gravity science Gravity-waves Payload Drag-free sensor + micro-thrusters Secondary launch via P-POD Launch ~ month drag-free ops in LEO Target program: Franklin/Edison Management NASA ARC: PM, SE, SMA, mission operations Stanford: Payload design, drag-free control, data analysis 9

10 Fiber-coupled Optical Cavity Small Sat Technology Objectives Raise TRL levels for: Frequency stabilized laser Fiber coupled optical train Beneficiaries: STAR, GRACE follow-on, LISA Mission Design Saudi-sat compatible secondary Any orbit, slow tumble OK Launch ~ month mission lifetime 55 kg 50 W Saudi Sat 3 Payload High-finesse Optical cavity Optical fiber coupling Low-cost laser Management NASA ARC: PM, SE, SMA, ops Stanford: Payload design, science KACST: Spacecraft Modulator photodiodes 10

11 Space-Time Asymmetry Research (STAR) Science Deviations from Einstein s predictions would cause us to rethink one of the foundational pillars of all of physical science Astro2010 decadal STAR will measure: Isotropy of speed of light to The direction of anisotropy Dependence on boost velocity Payload Molecular clocks Orthogonal optical cavities Low-noise comparator Multi-layer thermal enclosure Mission Design ESPA compatible on EELV Circular sun-sync 650 km orbit Launch ~ year lifetime Class D mission Management NASA ARC: PM, SE, SMA, ops Stanford: Payload design, science KACST: Spacecraft & Launch DLR: molecular clocks 180 kg 150 W ESPA 11

12 NASA Gravity-wave Concept Study Stanford experience led to LAGRANGE concept (LISA, ST-7, GP-B, STAR) 3 drag-free spacecraft in geocentric orbit Minimized payload: 1 test-mass (sphere), 1 laser, 2 telescopes Science LISA; Cost: $ G, Com-link: >100 LISA Small sat approach to tech demonstrations 2 t launch kg W Trade-space study Space Gravity Group s LAGRANGE Orbit Inertial Ref Metrology Heliocentric (4-5 options) Geocentric (3 options) LPF Cubes Sphere Cold atoms None Reflective Transmissive Arm locking Cavity, 12